Apparatus and method for pumping and cleaning a fluid

ABSTRACT

A METHOD, AND APPARATUS FOR THE PRACTICE THEREOF, INVOLVING THE USE OF A CONDUIT OPEN AT BOTH ENDS FOR CONDUCTING A MOVING, POLLUTED FLUID, SUCH AS GAS, THERETHROUGH. THE CONDUIT HAS AN INLET, MIXING SECTION ALONG ITS LENGTH, AND AN OUTLET EXPANSION SECTION OF GENERALLY DEVERGING CROSS-SECTION. ATOMIZERS OR SPRAY JETS ARE ARRANGED WITHIN THE INLET TO FINELY SPRAY A FLUID, MORE DENSE THAN THE POLLUTED FLUID, SUCH AS A LIQUID, IN UNIFORM DISTRIBUTION INTO THE MIXING SECTION, AT A VELOCITY WHICH APLPLROXIMATES AND A DIRCTION WHICH IS THE SAME AS THAT OF THE POLLUTED FLUID.

Sept. 28, 1971 v, 5T|NGEL|N ETAL 3,608,274

APPARATUS AND METHOD FOR PUMPING AND CLEANING A FLUID Filed Jan. 27, 1969 INVENTORS M a 6 5N w. 8 W .1 S m ML JM United States Patent 3,608,274 Patented Sept. 28, 1971 ice 3,608,274 APPARATUS AND METHOD FOR PUMPING AND CLEANING A FLUID Valentin Stingelin, Geneva, Switzerland, and Jules L.

Dussourd, Princeton, N.J., assignors to Ingersoll-Raud Company, New York, NY.

Filed Jan. 27, 1969, Ser. No. 794,025 Int. Cl. Bold 47/00 US. Cl. 55-84 14 Claims ABSTRACT OF THE DISCLOSURE A method, and apparatus for the practice thereof, involving the use of a conduit open at both ends for conducting a moving, polluted fluid, such as gas, therethrough. The conduit has an inlet, mixing section along its length, and an outlet, expansion section of generally diverging cross-section. Atomizers or spray jets are arranged within the inlet to finely spray a fluid, more dense than the polluted fluid, such as a liquid, in uniform distribution into the mixing section, at a velocity which approximates and a direction which is the same as that of the polluted fluid.

This invention pertains to methods and devices for pumping fluids, and to methods and devices for cleaning fluids, and in particular to methods and devices for simultaneously pumping and cleaning fluids.

Known methods, and devices for pumping fluids, involving jet pumps as they are known, commonly employ a conduit or pipe in which there is formed a constriction or neck which forms a venturi tube therein. The pumping fluid is forced through the neck, at great pressure, and high relative velocity, is formed into a spray, and creates a relative vacuum into which the fluid to be pumped is introduced. However, energy losses in these devices are high. Because of the marked disparity in the velocities of the polluted and pumping fluids, mixing and energy recovery are poor.

It is also known to practice the use of a single, solid stream of fluid, such as a liquid, as a primary or functional jet. A stream has some cleaning ability, but principally involves a turbulent scrubbing action to separate out pollutants from the fluid, such as a gas, being treated. Also, a stream is less efficient, as a pumping medium, than is a finely divided spray. And whatever limited efliciency the stream has, toward pumping, is made less so by the turbulence involved in the cleaning function.

There are, of course, methods which do use spray devices which cause the primary or functional jet of fluid to impinge on chamber surfaceswalls or partitions or the liketo break up the fluid jet into finely divided components. In such processes, the devices used exhibit a cleaning function which is reasonably adequate, but because of the back-splashing caused by the impingement, the pumping function thereof is nil.

We have determined from analyses that it is practical to both pump and clean a fluid in a highly eflicient manner not practiced heretofore which does involve the use of a finely divided spray of primary or functional jets of fluid, but in which the jets are not directed for impingement on surfaces and are not forced through pressure-generating constrictions.

Accordingly, it is an object of our invention to teach a method, and apparatus for the practice thereof, in which a spray of cleansing and pumping fluid is mixed with a polluted fluid to cause pumping of the latter fluid, and to cause pollutants to separate from said polluted fluid and to become entrained by said cleansing and pumping fluid.

Another object of our invention is to teach a method, and apparatus for its practice, in which a spray of cleansing and pumping fluid, of a given density, is mixed with a polluted fluid of lesser density to cause cleansing and pumping of said polluted fluid by said spray.

A feature of this invention comprises the provisioning of a conduit, open at both ends, with extended mixing and expansion areas of common axes, through which conduit a moving polluted fluid is directed, and in which mixing area a finely-divided spray of pumping and cleansing fluid is propelled at a velocity greater than that of the polluted fluid, uniformly distributed, and mixed with said polluted fluid.

Further objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying figures, in which:

FIG. 1 is an isometric projection of a preferred embodiment of a fluid cleaning and pumping apparatus, according to our invention, usable in the practice of our invented method; and

FIG. 2 is a horizontal sectional view, in isometric projection, taken along section line 22 of FIG. 1, of one of the inlet vanes. This view is on a much greater scale, than that of FIG. 1, to show the detail of the carriage of spray-jet devices on the inlet vanes.

Our inventive method of fluid cleaning and pumping contemplates the use of a pipe or conduit through which a moving, polluted fluid, such as gas, is to be conducted. Thus, the embodiment of a novel apparatus for practicing the method, shown in FIG. 1, comprises a conduit 10 open at either ends thereof. A first open end 12 and a second open end 14 are the inlet and outlet accesses, respectively.

Conduit 10 is formed of two, contiguous sections, mixing section 16, and expansion section 18, which sections have common axes. Mixing section 16 is of uniform crosssection throughout the length thereof. However, it could be of varying cross-section. The configuration of this cross-section is to be determined by the pattern of the pumping fluid spray-and of this, more is explained further on in this specification. Expansion section 18 is of varying cross-section-as a result of its diverging configuration relative the axis thereof.

Arranged horizontally across and within inlet end 12 are a plurality of spaced-apart vanes 20. Approximately a dozen vanes 20 are shown, however the number of vanes in the plurality thereof is not critical. Vanes 20 are of aerodynamic shape; i.e., they are formed as air foils to minimize the degree of resistance they will offer to the conduct of polluted fluid therebetween.

Polluted fluid requiring cleansing and pumping is introduced at inlet end 12 with a velocity, by way of example, of feet per second, although the acceptable velocity may fall within a given range of velocities which, we will say, are between 150 and feet per second. This polluted fluid, on having passed the vanes 20, is met with a pumping and cleansing fluid supplied thereat by piping 22. Piping 22 is arranged about mixing section 16, proximate to the inlet end 12, for through-connection with plumbing and nozzles carried by vanes 20.

As shown in FIG. 2, vanes 20 have pipes 24 arranged therewithin which are through-connected with small fluid lines 26 extending rearward (i.e., toward outlet end 14) therefrom. Lines 26 have the rearward ends thereof carried by nozzles 28. Nozzles 28 project rearward from the trailing edge of vanes 20 to which they are mounted, and have small spraying slots or orifices 30 at the terminations thereof.

Interconnection details, by means of which piping 22 and pipes 24 are joined, are not shown-such being a matter of design choice. Further, lines 26-, nozzles 28, and orifices 30 cooperate with each other as fluid spraygenerating means; the minute structural details are not given, as spray-generating means are widely known in this art. However, our spray-generating means contemplate means capable of both high nozzle efliciency and line atomization, simultaneously. Thus, our spraygenerating means are such as will receive a supply of pressured liquid, via piping 22, and discharge same out of orifices 30 in a finely-divided, mist-type spray, having droplet sizes ranging between 300 and 50 micrometers, and having a velocity within the velocity range, by way of example, of 160 to 190 fps.

Each vane carries a plurality of equi-distant nozzles 28, as FIG. 2 represents. Further, as there are a dozen or so vanes in the plurality thereof, a great number of nozzles are arranged, in a matrix-like pattern, within section 16, adjacent the inlet end 12 thereof. The spray pattern facility thereof, accordingly uniformly distributes the finely-divided, mist-type spray in section 16. When the configuration of section 16 is varied, in the fabrication thereof, the spray pattern must be varied accordingly to insure that the fine, fog-like spray is uniformly distributed throughout.

The spray pattern has presented before it consider able length of mixing section 16 in which to ditfuse and commingle with the polluted fluid. For example, the chord length of vanes 20 is in the order of three to four incheswith the nozzles 28 extending therebeyond but another one-eighth to one-quarter of an inch. Section 16, on the other hand, extends some three feet in the axial direction. Section 18 is approximately ten feet in length. Accordingly, the propelled spray fully diffuses throughout mixing section 16 and moves axially therealong toward separation section 18.

There is a limited disparity in the relative velocities of the polluted fluid and the primary or pumping and cleansing fluid. Accordingly, both pumping and cleaning efiiciences are achieved. The velocity of the polluted fluid is set forth as 165 fps. and that the primary fluid as 175 f.p.s. Pumping efficiency can be decreased, and cleaning efliciency increased, simply by increasing the disparity in relative velocities of the fluids. Therefore, such change in performance can be effected by varying the pressure of the source of the primary (pumping and cleaning) fluid supply.

Broadly, our inventive method comprises the provisioning of a conduit configured in accordance with that of conduit 20, admitting the polluted fluid through the conduit, and mixing a spray of cleansing and pumping fluid therewith. It is expected that our method will be practiced with a gas as the polluted fluid, and a liquid as the primary or cleansing and pumping fluid. However, our invention is not so limited. It can be practiced with fluids of whatever natures, providing only that the primary fluid be more dense than the polluted fluid.

As a pumping method and apparatus, our invention is superior to conventional ejectors because it takes advantage of the high density of the primary fluid and the excellent momentum exchange between the two fluids. Because of its high density, the primary fluid was a high energy level relative to that of the secondary, polluted fluid, without the necessity of it having a very high velocity. Because of the low velocity differential between the primary fluid and the polluted fluid (and the improved momentum exchange between the driving and the driven fluid) the resultant pumping efliciency is vastly superior to that achieved by conventional ejectors.

The ability of our method, and apparatus for the practice thereof, to remove pollutants from the polluted fluid arises as a result of impaction of the finely-divided components of the primary fluid with the pollutant particles and the resulting capture and entrainment thereof, by said primary fluid, in such a manner that the pollutant particles become collected by the primary fluid and may be withdrawn therewith at the outlet end, via conventional drainage means 32.

Fundamentally our inventive method teaches the step of pumping of a fluid with a finely-divided dense fluid. In practicing the invention with a liquid as the primary fluid, it is necessary to develop a fine, mist-spray thereof. Only if this fine division of the primary fluid is achieved can the high pumping efliciency be obtained. A number of necessary criteria have been established which must be met by the form of this fine division, this fine spray, if it is to operate satisfactorily. The spray must satisfy specific conditions in the size of the components, droplets or whatever, composing it. It must also satisfy specific conditions in the distribution of these components across the area of mixing section 16 through which the polluted fluid is conducted. Results obtained to date indicate that if the components are too large, the rate of deceleration, from spray release, at orifices 30, to outlet end 14, will be too slow and the transfer of the energy between the components and the polluted fluid will necessitate a long interacting distance. Likewise, for purposes of cleaning, the components of the spray, if too large, will provide an insuflicient amount of surface area for entraining pollutants thereon. The overall length of an apparatus using oversized spray components would be prohibitive from a standpoint of practicality. Vice versa, if the components are too small, the amount of energy necessary to achieve atomization becomes prohibitive. It would require extremely high primary fluid pressures, and in turn the high primary fluid pressures will produce a reduced eflieiency for the entire pumping apparatus. Small components of spray, however, perform efficient cleaning. Hence, it was determined that some prescribed range of spray component size was necessary for our practical apparatus to be built. This component size is that falling between 300 and 50 micrometers in diameter. In this prescription of component size we refer to the median mass size of the spectrum of components.

It is absolutely necessary that a highly uniform dis tribution of the spray components be achieved across the mixing section 16. It is to be noted that the polluted fluid pressure, as we move down the axis of the conduit 10, toward outlet end 14, continuously increases as a result of the interaction between it and the spray components. The spray of primary fluid, in effect, is supporting a pressure dilferential between the ends 12 and 16 of the conduit 10 by virtue of its own dynamic action. If the spray were such as to have gross nonuniformities where the density of the components thereof in one location is higher than the density thereof in another location, the weaker areas would not be capable of supporting the generated pressure rise and the polluted fluid would, so to say, leak back upstream, thus destroying the eifectiveness of the apparatus as a fluid pump. Thus, we have found it imperative to specify a tolerable variation of momentum of spray components across the mixing section 16 of not more than +10% of the mean value.

Our method, and the apparatus here taught for its practice, has an enormous built-in flexibility to a great variety of individual applications. For example, considering the use of water as a primary fluid, and air as the polluted fluid, then by varying the water-to-air ratio, or by varying the pressure of the water, it is possible to cover a wide range of pressure ratios in the air pumped by the apparatus. Our apparatus then is competitive with fans, as well as with blowers and compressors.

Our method, and the novel apparatus disclosed herein, are capable of handling situations not presently handled by such methods and apparatus, namely, the blowing or pumping of gases that are dirty, or corrosive, or that carry segments of solid matter, or are at a high temperature. It is capable of displacing ejectors in many applications because of its high potential efiiciency. Our novel method and apparatus are especially well suited to pump condensible vapors where the condensation would nor mally foul up the known, intricate mechanical cornpressors.

In the field of air or gas cleaning, an obvious application of our teaching is in scrubbers. The method and apparatus of our invention are capable of scrubbing solid matter out of a gas (as for example, fly ash, fumes, iron oxide, and other entrained solid particles). They are also capable of removing certain pollutant gases such as sulfur dioxide, and others, particularly if the spray used is a chemical other than water, or water with some appropriate solute.

Accordingly, While we have described our invention in connection with specific steps of method, and in connection with a specific embodiment thereof, it is to be clearly understood that this is done only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof, and in the accompanying claims.

We claim:

1. A method of cleaning and pumping a polluted fluid having a first velocity within a given range of velocities, comprising the steps of:

providing a conduit, open at both ends thereof, having extended mixing and expansion areas with common axes along the length thereof;

admitting said polluted fluid through said conduit; and

mixing only one other fluid with said polluted fluid;

wherein said other fluid comprises a spray of cleaning and pumping fluid, having a second velocity which is but fractionally greater than said first velocity, said spray being mixed with said polluted fluid to cause a pumping of said polluted fluid, and to cause pollutants to separate from said polluted fluid and to become entrained by said cleansing and pumping fluid.

2. The method of claim 1 wherein the fluid-spraymixing step comprises the mixing of a cleansing and pumping fluid which has a density greater than that of said polluted fluid.

3. The method of claim 1 wherein the fluid-spray-mixing step comprises the mixing of a liquid cleansing and pumping fluid.

4. The method of claim 1 wherein the fluid-spraymixing step comprises the step of uniformly distributing said spray at least within said mixing area.

5. The method of claim 1 wherein the fluid-spraymixing step comprising the step of uniformly distributing a spray of liquid cleansing and pumping fluid.

6. The method of claim 5, wherein said spray distributing step comprises forming said spray of droplet sizes ranging between 300 and 50 micrometers in diameter.

7. The method of claim 1, wherein said fluid-spraymixing step comprises the mixing of said cleansing and pumping fluid at least within said extended mixing area; and further including the step of removing said cleansing and pumping fluid, with pollutants entrained therewith, from said expansion area.

8. Apparatus for cleaning and pumping a polluted fluid having a first velocity within a given range of velocities, comprising:

a conduit, open at both ends thereof, having extended mixing and expansion areas with common axes along the length thereof;

said conduit being provisioned for admitting said polluted fluid therethrough; and

means for mixing only one other fluid with said polluted fluid;

wherein said mixing means comprises matrix-patterned means for mixing a spray of cleansing and pumping fluid with said polluted fluid to cause pumping of said latter fluid, and to cause pollutants to separate from said polluted fluid and to become entrained by said cleansing and pumping fluid.

9. The apparatus, according to claim 8, wherein:

said fluid-spray-mixing means comprises means for mixg a fluid of greater density than said polluted fluid.

10. he apparatus, according to claim 8, wherein:

said fluid-spray-mixing means comprises means for mixing a liquid.

11. The apparatus, according to claim 8, wherein:

said fluid-spray-mixing means comprises means for uniformly distributing said spray at least within said mixing area.

12. The apparatus, according to claim 8, wherein:

said fluid-spray-mixing means comprises means for uniformly distributing a spray of liquid at least within said mixing area.

13. The apparatus, according to claim 10, wherein:

said fluid-spray-mixing means comprises means for forming said spray in droplet sizes ranging between 300 and 50 micrometers in diameter.

14. The apparatus, according to claim 8, wherein:

said fluid-spray-mixing means comprises means for uniformly distributing said spray at least within said mixing area; and

further includes means for removing said cleaning and pumping fluid, with pollutants entrained therewith, from said expansion area.

References Cited UNITED STATES PATENTS 1,639,179 8/1927 Hamel 262-40X 1,734,677 11/1929 Kreisinger 261--VS 3,339,344 9/ 1967 Pallinger M 55-90 3,386,712 6/1968 Pafla 26l116 REUBEN FRIEDMAN, Primary Examiner R. W. BURKS, Assistant Examiner US. Cl. X.R. 261-116 

